Time After Time: A Second Look at Evolving Rash With Multiple Exposures to Amoxicillin

Abstract

Pediatric penicillin drug reactions may present in many forms such as erythema multiforme, serum-sickness, serum-sickness-like reaction (SSLR), Henoch-Schonlein Purpura (HSP), and urticarial vasculitis. Here, we review the case of a 13-month-old with atypical presentation of a drug reaction with increasing severity after each exposure to amoxicillin. We discuss the various differential diagnoses in comparison to our patient's presentation and conclude with the recommendation of considering timing and previous exposures in the diagnosis of drug-associated rashes in pediatric population.

A case of pediatric serum sickness like reaction (SSLR) after a 2-month re-exposure to amoxicillin

“…Clinicians commonly overlook and underdiagnose SSLRs to amoxicillin in the pediatric population due to lack of standardized diagnostic criteria [ 6 ]. Although there have been cases of pediatric amoxicillin SSLRs following re-exposure to the drug, to our knowledge, 2 months and 10 days is an unusually short duration between drug courses to develop such a reaction and has not yet been reported in the literature [ 2 , 5 ]. Moreover, our case helps contribute to our understanding of SSLRs due to the variability in its presentation.…”

“…SSLRs are more common in the pediatric population and often occur within 5–10 days of exposure when caused by beta-lactams [ 1 ]. There have been multiple cases of pediatric SSLRs following re-exposure to amoxicillin, however, to our knowledge, the time between re-exposure has not been well studied and 2 months and 10 days between two courses of amoxicillin is the shortest reported interval between development of an SSLR [ 2 , 5 ].…”